It's utter crap because many jobs in HK (and not Mac Do or 7/11) do not require HKU.CityU or CUHK education.
For example, HK has a huge entrepreneur scene - which does not require to graduate from HKU...
Besides, lots of people graduating from the other Universities, get jobs (not 7/11 or MacDo) in various companies in HK.
Not everyone becomes a successful CEO, Banker, lawyer, Consultant.
Many will remain office workers but not 7/11 staff.
Back to the Macdo thingy. while I know this isn't the majority, one of my childhood friend started his career at MacDo (after a family 'fight") on weekends selling fries and burgers, he worked 3 years there finally until he became the manager of 4 MacDo in the same city. he resigned (they wanted him to move to management in Paris but he did not want to move out of his childhood town) and for the past several years has been running a very successful restaurant (5 in total actually in the same area of France), where he makes more money than me....